How to encrypt data using symmetric key cryptography in Go?

To encrypt data using symmetric key cryptography in Go, you can use the crypto/cipher package along with a symmetric encryption algorithm like AES.

Here is an example of how you can encrypt data using a symmetric key:

package main

import (
	"crypto/aes"
	"crypto/cipher"
	"crypto/rand"
	"fmt"
	"io"
)

func main() {
	// Generate a random symmetric key
	key := make([]byte, 32)
	_, err := rand.Read(key)
	if err != nil {
		panic(err)
	}

	// Data to be encrypted
	data := []byte("Hello, World!")

	// Create a new AES block cipher with the key
	block, err := aes.NewCipher(key)
	if err != nil {
		panic(err)
	}

	// Generate a new random initialization vector
	iv := make([]byte, aes.BlockSize)
	_, err = rand.Read(iv)
	if err != nil {
		panic(err)
	}

	// Create a new AES block mode cipher using the block and iv
	mode := cipher.NewCBCEncrypter(block, iv)

	// Create a buffer to hold the encrypted data
	encrypted := make([]byte, len(data))

	// Encrypt the data
	mode.CryptBlocks(encrypted, data)

	// Print the encrypted data and the initialization vector
	fmt.Printf("Encrypted: %x\n", encrypted)
	fmt.Printf("IV: %x\n", iv)
}

In this example, we generate a random symmetric key using rand.Read. We then create an AES block cipher with the key and generate a random initialization vector (iv). Next, we create a new AES block mode cipher using the block and iv. Finally, we encrypt the data using the CryptBlocks method and print the encrypted data along with the iv.

Note: This example demonstrates how to encrypt data using AES in CBC (Cipher Block Chaining) mode. You can explore other symmetric key encryption algorithms and modes supported by the crypto/cipher package for different use cases.